Process for finishing spectacle frames and parts thereof

ABSTRACT

Plastic spectacle frames and parts for such frames, such as fronts, temples, and top rims are finish-polished by tumbling them in a barrel containing also scrap pieces of the plastic, pumice and conventional waxy polishing material, while maintaining the contents of the barrel refrigerated.

United States Patent Inventor Robert S. Abbey Rochester, NY. 739,689

June 25, 1968 June 29, 1971 Textron Inc.

Providence, 11.1.

Appl. No. Filed Patented Assignee PROCESS FOR FINISHING SPECTACLE FRAMES AND PARTS THEREOF 6 Claims, 11 Drawing Figs.

[52] 11.5. C1 51/314 [51] B24b 1/00 (50] Field of Search 51/314, 315, 316, 281

[56] References Cited UNITED STATES PATENTS 1,887,026 11/1932 Lach 51/314 2,062,671 12/1936 Lupo 51/316 2,402,967 7/1946 Lubenowu. 51/314 2,978,850 4/1961 Gleszer 51/316 3,324,605 6/1967 Lester 51/314 3,504,124 3/1970 Kittredge 51/314 FOREIGN PATENTS 855,865 12/1960 Great Britain 51/316 Primary ExaminerHarold D. Whitehead A!l0rneyB. Edward Shlesinger ABSTRACT: Plastic spectacle frames and parts for such frames, such as fronts, temples, and top rims are finishpolished by tumbling them in a barrel containing also scrap pieces of the plastic, pumice and conventional waxy polishing material, while maintaining the contents of the barrel refrigerated.

PATENTEU M29 I971 SHEET 1 0F 3 FIG. 1

INVENTOR ROBERT S. ABBEY /i ATTORNEY PATENTEDJUNZSIQ?! 3,589,080

saw 3 SF 3 FIG. 5 88 I 89 FIG. 10

90 INVENTOR ROBERT S. ABBEY FIG. 9 BY ATT(')RNlfY PROCESS FOR FINISHING SPECTACLE FRAMES AND PARTS THEREOF The present invention relates to a method for finishing plastic articles, and more particularly the zyl fronts and temples for spectacle frames.

Zyl fronts, as cut from a sheet of zyl stock, have rough sharp edges at the junctures of their sideand front, and of their side and back surfaces. To be usable these corners should be smooth and rounded off.

A primary object of this invention is to provide an improved method for smoothing and rounding off the rough corners of the cut stock, and for finishing the product with a high luster and polish.

Another object of the invention is to provide a process for this purpose which will be efficient and fast, and which can be performed with relatively simple, inexpensive apparatus.

Other objects of the invention will be apparent hereinafter from the specification and from the recital of the appended claims, particularly when read in conjunction with the accom panying drawings.

In the drawings:

FIG. I is a more or less diagrammatic side elevational view showing apparatus constructed according to one embodiment of this invention for practicing the invention;

FIG. 2 is a fragmentary side view on an enlarged scale showing how the cold air hood is mounted over the vibrator of the apparatus, and showing the connections thereto;

FIG. 3 is an end view of the parts shown in FIG. 2',

FIG. 4 is a plan view thereof;

FIG. 5 is a perspective view ofa rough stamping from which a pair of ornamental top rims for a spectacle frame may be made;

FIG. 6 is a front view of this stamping after a first polishing operation and showing the stamping drilled with the holes by which ornamental front shields and temple hinge plates may be attached to the top rims which are to be formed therefrom;

FIG. 7 is a rear view of this part;

FIG. 8 is a front view of a pair of top rims after being cut from the stamping and polished by the process of this inventron;

FIG. 9 is a perspective view showing a typical piece of zyl used as a polish carrying medium in the vibratory tumbling process of this invention;

FIG. 10 is a perspective view of a spectacle front such as may be rounded and polished by the present invention; and

FIG. 11 is a perspective view of a spectacle temple which may be polished by this invention.

Referring now to the drawings by numerals of reference, 10 denotes the barrel or vibrator, in which the articles, which are to be polished, are deposited for the polishing operation. A hood 12 encloses the vibrator, which is mounted by means of springs or other flexible support means 14 on a suitable foundation IS. The hood 12, which is out of contact with the vibrator, supports the upper flange or frame 18 ofa flexible bellows 20, which may be made of rubber, canvas, or other suitable flexible material. The bellows 20 is secured at its lower end to the collar 22 of vibrator 10.

The frame 18 is riveted or bolted to a channel-iron frame 24 to which there is welded the frame 26 ofa chamber 28, which is of generally rectangular shape in cross section.

A refrigerator 30 is connected to the vibrator 10 by a branch duct 32, the trunkline conduit 34, with which the branch communicates, and a branch conduit 36. The lastnamed conduit is connected by a flexible, bellows-type flexible coupling 38 with a pipe section 40 which communicates with the chamber 28.

A baffle plate 42 in the plenum chamber 28 (FIG. 2) directs refrigerated air coming from the refrigerator 30 into the vibrator 10. This baffle plate partitions the chamber 28 and divides it into two sections, one of which is connected to pipe section 40; and the other of which is connected to a pipe section 47.

The cold air delivered from the refrigerator circulates through the vibrator and exhausts through the bellows coupling 20 into the chamber 28, and thence through the pipe section 47 and a flexible, bellows-type connection 49 into a branch conduit 51 which communicates with the trunkline duct 53. A bypass duct 55 leads from the trunkline conduit 53 to the refrigerator 30. The air flowing in the duct 55 enters the refrigerator at the bottom thereof after passing through a conventional filter 57. There is therefore a circulating system pro vided through which the cold air travels from the refrigerator to main line duct 34 and the vibrator, then being heated by the friction generated in the tumbling barrel travels back through the main line duct 53 to the refrigerator to be cooled again.

The flexible, bellows-type coupling 20 between the vibrator l0 and the hood 24 dampens vibrations and insulates the hood and the parts supported thereby from the vibrator.

The refrigerating unit is operated by a conventional condenser 60 provided with refrigerating; coils 62, a motor 64, and a fan 66. The condenser is connected with the refrigerator by a pipe line 68. A drain 70 carries off water and condensate from each refrigerator unit.

A motor-driven fan 33 (indicated diagrammatically), which is mounted on top of the refrigerator unit 30, to communicate with the duct 32, or mounted in the duct 32 itself, circulates the cold air from the refrigerator through ducts 32, 34, and 36 into the vibrator unit.

The conduits 36 and S1 of the vibrator unit are connected together by a short duct 52. A pivoted damper 54 in duct 52, and a pivoted damper 56 in duct 36 below the cross duct 52 are provided to control the temperature of the air in the vibrator unit 10.

The hood 24 is closed in use by a swinging hinged loading door 74, which can be rocked upwardly into the chamber 28. Parts, which are to be polished, are loaded into the vibrator when this door is open. The door is closed by a pivoted latch 76 which engages a keeper 78 (FIG. 4) on the hood. A handle 80 permits manipulating the door. The door is actually a part of the hood.

In use, the articles, which are to be polished and have their rough edges smoothed off, such as the zyl fronts F (FIG. 10) of spectacle frames, temples T (FIG. Ill), or the decorative top rims R (FIGS. 5 to 8), are put into the vibrator 10 together with generally diamond-shaped pieces (FIG. 9) of zyl, some pumice, or other finely powdered abrasive, ordinary waxy polishing material, water, and, if required, water sof' tener.

The pieces 90 are made of the same material as the fronts, temples, and top rims, namely, of zyl (cellulose acetate). The pieces 90 are scrap pieces, shaped preferably, however, to a generally diamond shape as shown in FIG. 9 but having recesses 91 in opposite sides.

The media 90 is first cooled to about 48 F. A sufficient quantity of the media 90 is then placed with the pumice, waxy polishing material, water, and, if required, water softener, in the tumbling barrel or vibrator, which is kept refrigerated; and the vibrator is run for about 2 minutes to intermix all the ingredients. Then the spectacle fronts, and/or temples, and/or top rims, which are to be finished, are loaded into the barrel, and the connection to the refrigerator unit is made.

The vibrator unit is then run at about 1,650 vibrations per minute for 1 hour. Then additional waxy polisher (one ounce for an ordinary size tumbling barrel) and water (a cup for an ordinary size barrel) are added; and the unit is restarted and run at the previous number of vibrations per minute for l more hour. After the second hour, further waxy polisher (4 ounces, for instance) and water (2 cups, for instance) are added; and the unit is again run at 1,650 vibrations per minute for another hour. This completes thejob.

The water and waxy polisher are charged repeatedly, as described, duringthe cycle to maintain the bubbling action necessary to explode the pumice across the surfaces of both the diamond-shaped scrap pieces 90 and the spectacle fronts, or temples, or top rims, during the run. This process removes scratches from the fronts and rounds off the edges of the fronts.

A conventional waxy material or emulsifier may be used.

For the pieces 90 it is easiest to use scrap from the top rim blanks 85. A sheet of zyl is first stamped out to form an irregular shape as shown at 85 in H0. 5, having a top arm 86, a lower arm 87, and two side arms 88 and 89. The side arm 88 has outwardly projecting portions at top and bottom shaped to provide what will eventually become the temple ends of a pair of top rims, and the outer side of the side arm 89 is shaped so that when the part 85 is cut in two, it will form what eventually will become the nasal ends ofa pair of top rims. After the first polishing operation, the part 85 will have the shape shown in FIGS. 6 and 7 at 85. The arms 86, 87, 88, 89 will be considerably thinned down, as denoted at 86', 87', 88', and 89, and the rough edges will be smoothed off. The parts 85 are then removed from the tumbling barrel or vibrator; and holes 95 are drilled in them for receiving the rivets by which the decorative shields may be attached to the fronts at the temple ends of the top rims. Recesses 96 will also be milled out of the backs of the parts 85 to receive the temple plates, by which the temples may be hinged to the top rims. The part 85 will then be cut in two, to separate the two top rims 86", 87" from one another; and the separated top rims 86", 87 will then be returned to the tumbling barrel for the final finishing and waxing operation. The two finished top rims are shown at 86 and 87", respectively, in FIG. 8.

When the pieces 85 are cut in two, as described, the scrap, which is left, will be shaped like the parts 90 and may be used as media for spreading the pumice and wax.

In a production line installation there will be several units, comprising vibrators and refrigerators. Thus, as indicated in FIG. 1, several vibrators and refrigerators may alternate down a line of machines and be connected to the main line ducts 34 and 53 just as are the vibrator l and refrigerator 30 shown. ln such an installation, a pair of ducts 51, 36 serves one vibratory unit, and a pair of ducts 32, 55 serves one refrigerating unit.

The media 90 are made from trimmings, particularly from a cut-apart operation on top rim stampings. While diamondshaped media is preferred, other pieces of scrap material in various sizes and shapes may be employed.

The polishing operation may be performed in several steps. For instance, after cutting, a first finish tumbling operation may be performed using only the media 90, water and pumice; and then a second tumbling operation may be performed using the media, but with or without the pumice, and with wax.

While the invention has been described in connection with a specific embodiment thereof, and a particular use therefor, it will be understood that it is capable of further modification and use; and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth, and as fall within the scope of the invention or the limits of the appended claims.

l claim: 1. A process for polishing plastic parts of spectacle frames, comprising:

placing the parts in a refrigerated receptacle with scrap pieces of plastic, wax, water and a finely powdered abrasive, and effecting a tumbling operation while keeping the ingredients in the receptacle refrigerated. 2. A process as claimed in claim 1 wherein said scrap pieces are generally diamond-shaped and have sharp edges.

3. A process as claimed in claim I, wherein the scrap pieces are of the same material as the parts to be polished.

4. A process as claimed in claim 3, wherein the scrap pieces of plastic are cooled prior to placing them in the receptacle.

5. A process for polishing plastic parts of spectacle frames, comprising cutting plastic top rim stock in two to form two tope rims and scrap, cooling the scrap to a temperature of about 48 F., placing a quantity of the cooled scrap, together with the parts to be polished, in a refrigerated receptacle, adding a wax to the receptacle, water, and a finely powdered abrasive, and tumbling the receptacle while keeping its contents refrigerated. 6. A process for polishing plastic parts of spectacle frames, comprising cutting plastic top rim stock to form a plurality of top rims and scrap from the plastic stock, cooling the scrap to a temperature ofabout 48 F., placing a quantity of the scrap together with pumice, a waxy polishing material, and water in a receptacle, subjecting the contents of the receptacle to a brief tumbling operation to intermix said contents, then adding to the receptacle the plastic parts that are to be polished, and again subjecting the contents of the receptacle to a second tumbling operation for a period of time substantially greater than that of the first tumbling operation, and maintaining the contents of the receptacle refrigerated throughout the second tumbling operation. 

1. A process for polishing plastic parts of spectacle frames, comprising: placing the parts in a refrigerated receptacle with scrap pieces of plastic, wax, water and a finely powdered abrasive, and effecting a tumbling operation while keeping the ingredients in the receptacle refrigerated.
 2. A process as claimed in claim 1 wherein said scrap pieces are generally diamond-shaped and have sharp edges.
 3. A process as claimed in claim 1, wherein the scrap pieces are of the same material as the parts to be polished.
 4. A process as claimed in claim 3, wherein the scrap pieces of plastic are cooled prior to placing them in the receptacle.
 5. A process for polishing plastic parts of spectacle frames, comprising cutting plastic top rim stock in two to form two tope rims and scrap, cooling the scrap to a temperature of about 48* F., placing a quantity of the cooled scrap, together with the parts to be polished, in a refrigerated receptacle, adding a wax to the receptacle, water, and a finely powdered abrasive, and tumbling the receptacle while keeping its contents refrigerated.
 6. A process for polishing plastic parts of spectacle frames, comprising cutting plastic top rim stock to form a plurality of top rims and scrap from the plastic stock, cooling the scrap to a temperature of about 48* F., placing a quantity of the scrap together with pumice, a waxy polishing material, and water in a receptacle, subjecting the contents of the receptacle to a brief tumbling operation to intermix said contents, then adding to the receptacle the plastic parts that are to be polished, and again subjecting the contents of the receptacle to a second tumbling operation for a period of time substantially greater than that of the first tumbling operation, and maintaining the contents of the receptacle refrigerated throughout the second tumbling operation. 